Morphogenesis of human placental chorionic villi: cytoskeletal, syncytioskeletal and extracellular matrix proteins

Abstract

Immunocytochemical and ultrastructural methods were used to investigate the distribution of a family of structural proteins in the human placenta near term. These reveal the distribution of cytoskeletal and ‘syncytioskeletal’ components that may account for some of the more obvious micromorphological features of placental structure. In the syncytiotrophoblast a potentially supporting structure ‘the syncytioskeletal layer’ is described. It is an apparently continuous and complex polymeric network covering the villous tree, a surface of the order of 10m 2 in area in the full term placenta (Aherne & Dunnill 1966). It is suggested that this layer plays a part in morphogenesis of the villous tree.

A Message from the Human Placenta: Structural and Immunomodulatory Defense against SARS-CoV-2

“…Second, the STB contains an unusually dense cytoskeletal network creating a shielding brush border at the apical surface [24]. Interestingly, based on a murine trophoblast stem cell model, it has been shown that the disruption of actin polymerization with cytochalasin D decreases syncytial elasticity and correlates with increased bacterial invasion, suggesting an important involvement of the actin cytoskeleton in host defense mechanisms [25].…”

Fetal Capillaries of the Villous Stroma in the Full-Term Diabetic Human Placenta: An Electron Microscopic Study on the White's Class A

“…Many osmiophilic granules and membrane-bounded heterosomes are also seen together with a large number of 10 nm microfibrillae, which are composed of the intermediate filament protein (probably vimentin) between actin and tubulin (Ockleford et al, 1981). One may therefore conclude that the passage of certain materials, especially large molecules, is likely to occur at a very high rate.…”

“…This suggests a specific placental association, possibly related to hte immunological isolation of the fetus (Bray et al, 1975;Johnson and Faulk, 1978). On the other hand, using immunofluorescence microsopy, fibronectin has been demonstrated in both trophoblastic and endothelial basement membranes (Ockleford et al, 1981). Laminine is also specifically located on both membranes which are revealed by immunoclectron microscopy (Foidart et al, 1980).…”

“…The microfilaments of the endothelium of the capillaries of the human placenta are conspicuous and characteristics. According to Ockleford et al (1981) the intermediate filaments (10 nm) appear to form tresses which act as circumferential supports, as a cytoskeleton, for the fetal capillary endothelial cells which ramify in the villous stroma. By securing a constant vascular movement they allow more efficient interchange between the maternal and fetal perfusion.…”

Mecanismos de transmissão transplacentária de Toxoplasma gondii em modelos murinos e em cultura de células

“…Muitos estudos mostraram que as células SYN, além de restringirem o crescimento de diversos microrganismos, também foram descritas como resistentes à invasão por muitos patógenos, incluindo T. gondii. Alguns estudos mostraram que SYNs não possuem junções intercelulares, o que dificultaria a invasão, pois muitos patógenos usam essas moléculas para invadir as células (OCKLEFORD et al, 1981;. Também foi descrito que estas células apresentam uma rede de citoesqueleto e microvilosidades ramificadas que podem inibir a entrada dos patógenos (CANTLE et al, 1987).…”